<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>线性渐变</title>
    <link rel="stylesheet" href="./index.css">
</head>
<body>
    <!--可控比例的虚线工具-->
    <div class="dashed"></div>

    <!--带框三角-->
    <div class="tri"></div>

    <!--线性渐变生成加减号-->
    <div style="margin-top: 10px;">
        <div class="box"><div class="add"></div></div>
        <div class="box"><div class="sub"></div></div>
    </div>
</body>
</html>